Environmental Protection Agency (EPA) Acting Assistant Administrator for Air and Radiation Janet McCabe, testifies on Capitol Hill in Washington, Tuesday, Sept. 29, 2015, before a Senate Environment and Public Works Committee hearing on “Economy-wide Implications of President Obama's Air Agenda.” Facing a court-ordered deadline, the Obama administration is preparing to finalize stricter U.S. emissions limits on smog-forming pollution linked to asthma and respiratory illness. (AP Photo/Manuel Balce Ceneta)WASHINGTON (AP) — The current federal limit on smog-forming pollution linked to asthma and respiratory illness “is not adequate to protect the public health,” a top environmental regulator said Tuesday.